Electro-enhanced solid-phase microextraction with covalent organic framework modified stainless steel fiber for efficient adsorption of bisphenol A.

In this work, electro-enhanced solid-phase microextraction (EE-SPME) and covalent organic framework (COF) were adopted to improve the extraction efficiency. A conductive COF synthesized of 2,6-diaminoanthraquinone (DQ) and 1,3,5-triformylphloroglucinol (TP) was in situ bonded to the stainless steel wire via facile solution-phase approach and used as the EE-SPME fiber coating to preconcentrate a typical endocrine disruptor bisphenol A (BPA). Compared with conventional SPME, the DQTP bonded fiber coupled with EE-SPME device exhibited higher extraction efficiency and achieved extraction equilibrium within 10 min. The proposed approach based on EE-SPME and gas chromatography coupled with flame ionization detector gave a linear range of 0.05-10 μg mL and detection limit of 3 μg L (S/N = 3) with good precision (<6.7%) and reproducibility (<7.1%) spiked with 0.1, 0.5, 1.0 μg mL BPA. Quantitative determination of BPA in extracts of food packagings (mineral water bottles, milk boxes and milk tea cups) was achieved with recoveries from 88.6 to 118.0%.